1. Field of the Invention
The present invention relates to methods and means for inserting pipe into a well. More specifically, the present invention relates to systems, methods, and apparatus for attaching conduit used as control lines and injection lines to a string of pipe being inserted into a well.
2. Description of the Prior Art
Oil and gas wells are sometimes equipped with tubing lines or small diameter conduits that regulate the opening and closing of valves contained within the pipe string or that inject fluids into the well. The lines typically are secured to the outside of the pipe string. The lines used for control can regulate the opening and closing of subsurface valves employed in the production pipe strings in offshore wells to permit the wells to be closed in below the sea bottom. The lines used for injection are frequently employed to add corrosion control or other treating fluids to the fluid being produced from the well. The lines, or conduits, referred to herein generically as "control lines," are relatively small diameter, continuous, thin-walled tubes that can easily be damaged during their installation into the well.
The conventional technique for installing control lines with the pipe string requires that the control lines extend alongside the pipe through the pipe clamp, "slips," or "spider" used to support the pipe string from the rig floor. The control line is clamped to the pipe, and the clamp, control line, and pipe are lowered through the open spider into the well. Special provision must be made in the spider so that the control line may safely extend past the pipe-gripping slips contained within the spider. If the control line becomes trapped radially between the slips and the pipe, or circumferentially between the slip segments, the control line will be crushed or ruptured. To avoid this, the control line is typically positioned in a gap between adjacent segments of the slips or is passed through a special recessed area formed through or alongside the central opening of the spider body.
In some offshore installations, it is necessary to employ several control lines with each string of production tubing. Deep, offshore well completions may require as many as four or more separate control lines, or packets of control lines, with each string of production pipe that is run into the well. The presence of multiple control lines requires that the lines be attached to the pipe in a circumferential arrangement that will permit them to clear the slip segments in the spider. Such an arrangement may not necessarily be the best arrangement for the well design. The clamping mechanisms required to secure multiple control lines to the pipe may also interfere with the operation of the spider slips. The requirement for multiple control lines to extend through the spider also increases the danger of damage to the lines and renders the process more time-consuming and difficult.